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View Full Version : Converting AVI with diff MP3 encoding causes visual/audio out of sync


Jivrashia
24th December 2005, 10:50
Hi all.

I wasn't able to determine which topic best suited my query, so I posted it here.

I have several AVI episodes, which is encoded as Xvid + MP3. I'd like to convert them into a DVD friendly format so that I can play it on my DVD player.
And so I tried converting and succeeded in doing the first 3 episodes into one DVD (DVD5)). Great! I simply followed the "AVI to DVD guide" here http://www.doom9.org/mpg/avi2dvdr.htm. This was probably made easy since the encoding was same on all three eps (especially the audio, which is MP3 VBR 48KHz).

Then I ran into problem in the next 3 episodes, where one of the ep had a different sampling rate (32KHz). I should explain myself here that I first start out by joining the AVIs using VirtualDub (as per the guide mentioned above). From there I'd extract out the audio as a WAV, then convert it to AC3. Unfortunately VirtualDub won't allow me to do this for this batch since the audio sampling rate is different (48KHz vs 32Khz). So, instead, I extract out the video and audio separately, joined the video-only files on their own (using VirtualDub), joined the audio-only files on their own, did the conversion (AVI->MPEG-2, WAV->AC3), and finally converge them together using Ifoedit (plus I generate my own celltime.txt containing the frame number of each eps for rudimentary chaptering - don't need menu et al).
PROBLEM - from the second ep/chap the visual and audio is out of sync by a split second (< 1sec)! The audio is delayed! I'm speculating that the problem was in the audio extraction/decoding/encoding part, but unfortuately I have little knowledge of how to deal with it.

So, to explain myself further, here is how I (mis)handled my audio. I extracted out the audio separately from each of the three eps using VDub (select "Full processing mode" then "Save WAV..."). Then I joined the WAV files using a shareware called WAV Joiner. After IfoEditing it resulted in visual/audio sync problem. Next I tried to extract the audio using VDub "Direct stream sopy" then "Save WAV...". I assumed the files were MP3 still so I used Winamp's WAV writeout plug-in to join and convert the files to one WAV file. Again, after IfoEditing visual/audio is still out of sync.

Hope I've provided enough information. Was wondering if anyone can point out what I might be doing wrong to introduce this delay(or the reverse).

Thanks in Advance.
Jiv.

ammck55
24th December 2005, 16:42
Welcome to the forum:

It sounds as if you have an audio delay issue. Pull out the original discs and run straight backups, bypassing the XviD encoding; if you don't have the original discs in your possession, we can't help you. Look to the Forum Rules at the top of the page and the Announcement at the top of the Newbies forum for further information.

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